The present invention relates generally to ironing mechanisms for use in the manufacture of metal containers. Particularly, the invention relates to a tool pack assembly used in the drawing and ironing of bodies for two piece steel and aluminum cans. More particularly, the invention relates to improved floating die module assemblies for use in a tool pack assembly for the manufacture of metal containers.
The tool pack assembly of the present invention is an improvement of the tool pack assembly disclosed in U.S. Pat. No. 4,554,815 ('815 Patent) to Weishalla, entitled Tool Pack Assembly and assigned to the assignee of Applicant's present Application. The tool pack assembly of the '815 Patent, incorporated by reference herein, utilizes floating ironing and guiding dies which axially realign within the internal housing area subsequent withdrawal of the ram from the formed container. Specifically, the centering and guiding means of the die modules of the tool pack assembly have been improved by the teachings of the present invention.
Tool pack assemblies typically house fixed and/or movable die elements which engage with rapid cycling softer materials positioned about a ram device for decreasing thickness of the material. Spatial control of the die elements along and normal to the axis of movement of the ram, is imperative for manufacturing production, quality and efficiency. The tool pack assemblies and die modules of the present invention improve these manufacturing parameters by providing improved dampening means to center and bias the die modules of the tool pack.
The improved dampening means of the invention for biasing a die assembly comprises an elastomeric spring member and a cooperating rigid contact member. The elastomeric urethane dampening member provides advantages over the coil springs used in the prior art, i.e., increased life, wider range of spring forces, and increased reliability of performance. The contact members further provide a plurality of wear surfaces which further increase the performance and life of the dampening structure. The cooperating dampening means components are positioned and held in die module housing cavities in which the components are easily accessible for maintenance and replacement in contrast to the coil springs used in prior art tool pack assemblies.
The die module housing of the present invention also has an improved structure by utilizing wear plates which are easily removable, thereby providing a more effectively serviceable and maintainable die module assembly. In the past, upon wear the entire module housing required grinding, for example, whereas in the module housing of the present invention only the wear plates need to be serviced. The tool pack assembly of the present invention provides improvements and advantages over those of the prior art.